1. Field of the Invention
The invention relates to a method of production of iron, particularly pig iron, from iron compounds by a two-stage process of first pre-reducing the iron compounds in a first chamber with a rotationally symmetrical wall and a vertical axis, and secondly further reducing the iron compounds in a second chamber located beneath the first chamber. In the second chamber the further reduction of the iron compounds takes place with fuel and oxygen being supplied to the second chamber to produce a reducing gas which passes upwardly into the first chamber to effect the pre-reduction there. Oxygen is supplied to maintain a combustion in the reducing gas in the first chamber, so that the iron compounds at least partly melt and pass down into the second chamber. The invention also relates to an apparatus for carrying out this method.
2. Description of the Prior Art
A method and apparatus of this type is known from NL application 257,692 (to which FR-A-1314435 corresponds). A similar disclosure is in Steel Times International, GB, 1993, March No. 2, page 24. The first, upper chamber is known as a melting cyclone or cyclone pre-reducer. Other two-stage processes for pre-reducing iron compounds are also known, such as for example a process in a fluidized bed reactor. However, the pre-reduced iron compounds from the fluidized bed in that process are introduced in solid state into a metallurgical vessel, the so-called melting reactor. This places high demands on the post-combustion of the reaction gases in the melting reactor required for creating the necessary heat in the melting reactor. The melt is only partly helped by this heat which is released above the melt. In the process of the type of the present invention, however, the post-combustion can take place in the first chamber and the heat released from this transfers directly to the iron compounds.
The present inventors have studied this type of process and have obtained a new and deeper insight into this technology.